there's various reasons your car will consume oil. could be as simple as needing a new pcv valve, or it could be cracked ringland(s). subaru considers consuming 1qt every 1k miles normal.... though in reality, if you're consuming that much, theres probably something wrong. the inlet, intercooler, throttle body hose will have a small puddle and film of oil in it, and thats normal. blow-by can become an issue if your pcv is clogged or stuck and the amount of blow-by will massively increase and impact the amount of oil you consume.